az_ifpack_iterate.c

/*@HEADER
// ***********************************************************************
// 
//       Ifpack: Object-Oriented Algebraic Preconditioner Package
//                 Copyright (2002) Sandia Corporation
// 
// Under terms of Contract DE-AC04-94AL85000, there is a non-exclusive
// license for use of this work by or on behalf of the U.S. Government.
// 
// This library is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 2.1 of the
// License, or (at your option) any later version.
//  
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//  
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA
// Questions? Contact Michael A. Heroux (maherou@sandia.gov) 
// 
// ***********************************************************************
//@HEADER
*/

/*
 * This code is a wrapper layer around AZTEC.  It takes the real and imaginary
 * parts of a complex valued linear system and forms an equivalent real system,
 * calls AZTEC to solve the real system and returns the solution.
 */

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include "az_aztec.h"
#include "az_ifpack.h"

void AZ_ifpack_iterate(double *x, double *b,
            int *options, double *params,
            double *status, int *proc_config,
            AZ_MATRIX *Amat )

/*******************************************************************************

  Author:          Mike Heroux, SNL, 9222
  =======

  Return code:     void
  ============

  Parameter list:
  ===============

  x:               On input, contains the initial guess, On output 
                   contains the solution to 
                   the linear system.

  b:               Right hand side of linear system.

  options:         Determines specific solution method and other parameters.

  params:          Drop tolerance and convergence tolerance info.

  status:          On output, indicates termination status:
                    0:  terminated normally.
                   -1:  maximum number of iterations taken without achieving
                        convergence.
                   -2:  Breakdown. The algorithm can not proceed due to
                        numerical difficulties (usually a divide by zero).
                   -3:  Internal residual differs from the computed residual due
                        to a significant loss of precision.

  proc_config:     Machine configuration.  proc_config[AZ_node] is the node
                   number.  proc_config[AZ_N_procs] is the number of processors.

 Amat:             The matrix operator, stored as an AZ_MATRIX structure.

  Internal Parameter list:
  ========================

 x:                Komplex version of initial guess and solution.
 b:                Komplex version of RHS.
 Prec:             Preconditioner stored as an AZ_PRECOND structure.

  Overview
  ========

*******************************************************************************/


{

AZ_PRECOND *Prec;    /* Structure representing entire preconditioner.        */
                    /*                                                      */

   AZ_ifpack_prec_create (x, b, options,  params, proc_config, Amat, &Prec);

   /* solve linear system using Aztec. */

   AZ_iterate(x, b, options, params, status, proc_config, Amat, Prec, NULL);

   AZ_ifpack_prec_destroy (options,  params, proc_config, Amat, Prec);

/* AZ_ifpack_iterate*/
}

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